PPM调制光纤耦合多孔径接收系统性能研究

The performance of fiber-based FSO with multiple apertures receiver system was studied for pulse position modulation (PPM) . Expressions of PPM modulated signal-to-noise ratio (SNR) and bit-error rate (BER) for fiber-based FSO multiple apertures receiver system were presented based on the probability density function of Gamma-Gamma intencity distribution and non–central chi-square fiber coupling efficiency distribution under atmospheric influence. Selection combining (SC), equal gain combining (EGC) and maximum ratio combining (MRC) were considered to be three signal combining methods for multiple apertures receiver system. The BER performance of 4PPM modulted SC, EGC and MRC fiber-based multiple apertures receiver system and single aperture receiver system with the same total aperture area were comparative analyzed by Monte Carlo simulation. The BER performance of fiber-based multiple apertures receiver systems in 4PPM and 8PPM modulation modes were directly compared for different combining methods.